I like the way Sonnie has his setup with the 740 and a 2:92 rear gear you won't hurt the 3406 pulling it down to 900 rpm just put your foot in it and watch it go, it will blow it's puff of black smoke after that off to races a fantastic trouble free engine, if you get ever get a chance Red Ruby has a 3406 in his Eagle with a nice setup I think he is close to you

Most of the Eagles here in the west that have been changed have the Cat engine back east it seems to be the 60 series could be because we have mountains and they have hills sorry guys I could not resit I would say there are more 3406 Cat engines in Eagles than any other brand Southern Oregon Diesel started that trend years ago

On my 8V-71, I change the oil at 5,000mi. When I change it, it turns black right away. What's amazing about my Cat 3406B, it has about 200,000mi on the in frame. I changed the oil about 1,000mi ago and it still is light brown in color.

The mechanical 3406B is so good, Cat is still making it-although now the 3406C for 3rd world countries for gens and pumps. Much rather have the 3406 over any Cummins NTC engine. Good Luck, TomC

I switched my 13spd Roadranger to the Allison HT740 on my truck. It is a little weird since the Cat has a full range speed governor-just have to learn how to regulate the transmission with your foot. With my 11R-24.5 and 3.55 rears, my 65mph cruise is right at 1830rpm. 75mph is 2112rpm. I could go to 3.08 rears, but I don't think the cost of changing two rear ends (tandem's) will make for enough money saved with fuel. Besides, I usually cruise around 60 which is 1690rpm. Good Luck, TomC